Evaluation Of Germplasm Resources Of Bermudagrass Materials From Regions With Different Latitudes And Longitudes

Bermudagrass(Cynodon dactylon)belongs to the Chlorideae tribe of Eragrostoideae subfamily.It is one of the most important warm season grass species in the world.It grows mainly in the warm and humid tropical and subtropical regions.In China,it mainly distributes in the southern provinces of the Yellow River.Bermudagrass is the most widely distributed plant in the world(world record No.:20130500226).The complex habitats lead to the abundant variation of Bermudagrass in China.It is not clear what kind of morphological and photosynthetic characteristics Bermudagrass shows along latitude and longitude.As a widely used grass in various fields,the development,utilization,domestication and breeding of high-quality wild Bermudagrass are speeding up with the development of society and the requirement of grass species localization.The purpose of this study is to compare the characteristics of wild Bermudagrass germplasm in regions with different latitude and longitude,so that high-quality grass species can be secreened,and reference can be provided for the breeding,development and utilization of domestic high-quality Bermudagrass.By comparing the morphological characteristics and some chlorophyll fluorescence parameters of wild Bermudagrass materials from 27 regions with different longitude and latitude in China,the study shows that:(1)There are rich morphological differences and diversities in the wild Bermudagrass materials.Generally speaking,with the increase of the latitude of the regions,the root/shoot ratio,the stolon internode length and the plant height increase,and the stolon diameter decreases.The leaf color of varieties in low latitude regions is deeper than that in high latitude regions.On the longitude gradient,from east to west,the color of wild Bermudagrass materials tends to be lighter,and the plant type of western varieties is generally larger.The morphological indexes have a change rule in small geographic range,but do not simply increase or decrease along with the longitude and latitude.The diversity index of most indicators has no significant correlation with environmental factors;(2)The Fv/Fm value of wild Bermudagrass materials has little change under natural conditions.Except for the wild Bermudagrass materials from Tianshui,the difference of Fv/Fm of wild Bermudagrass materials in most regions is not significant,all of which are higher than 0.7,indicating that the photosynthetic efficiency of most wild materials is high.On the latitude gradient,the value of Fv/Fm and Fv/Fo of materials from low latitude regions are slightly higher than those from high latitude regions,which indicates that the photosynthetic efficiency and potential of plants from low latitude regions are higher than those from high latitude regions;(3)The difference of morphology and photosynthetic capacity of wild Bermudagrass materials from different regions is more like the reflection of its plasticity,these changes may be due to the adaptation of Bermudagrass materials to the different environment;(4)There are abundant chromosomal ploidy diversity in the wild Bermudagrass from different regions.There is a significant correlation between the morphological characteristics of stolen and leaf and the chromosome ploidy level of wild Bermudagrass materials.The plant type of higher ploidy level materials is usually larger;(5)According to the morphological characteristics,wild bermudagrass materials from 27 regions are roughly divided into 4 categories.The first category is materials from Cixian and second category is materials from Huixian,the plants of these two categories are low and suitable for the lawn;the third category includes materials from 7 regions including Zhengzhou,which are tall and suitable for breeding as forage grass;the fourth category includes materials from 18 regions including Zhumadian.According to the chlorophyll fluorescence parameters,they can be divided into three categories.The first category mainly includes materials from 5 regions including Cixian,most of which are from high latitude and with relatively low photosynthetic capacity;the second category mainly includes materials from 20 regions including Xuchang,with the strongest photosynthetic capacity;the third category includes materials from Liuyang and Tianshui,with the worst photosynthetic capacity.Through the comprehensive comparison of morphology and photosynthetic capacity,the feeding type suitable for local climate are selected as "Jingyang 2","Fufeng 30" and"Baoji 1"."Cixian 8" and "Huixian 16" are materials suitable for lawn.